I take it the bird bath thing will be where your officiant stands? If so, can the bird bath (if it's not full of water) act as a podium of some sort...?
I think there are lots of options... Give that you have 2 weeks, it might be a little late to talk to your florist for ideas, but it's worth a shot. A simple arch or post & lentil structure can be made and decorated with fabric or fresh or
silk flowers from your florist or even by you and your team. Or even marking the "altar" for the ceremony with a beautiful potted plant on either side can work. I've seen random archways or simple structures for sale at Lowes or
Home Depot. I think you'll have a bit more variety at a garden center or nursery. If you don't want to spend the money, talk to some friends and family and see if someone can build one for you. Then it would be completely custom!
A couple of photos for inspiration:



Chairs along the aisle can be decorated in a huge variety of ways. Ribbons, small bouquets of flowers, hanging in little buckets, flower pommanders, bows, etc. You can search through the images on this website along with other wedding sites. I
actually found a lot of good inspiration from here and from TheKnot.
The ground shown looks like it would be ideal for an aisle runner. There have been a couple of threads on here talking about how to DIY one. It's not too hard. You could even have flower petals strwen about (if the site allows it)
Good Luck!